The current crisis in and over Qatar has serious implications for the entire Middle East. If you haven't been following it, see these articles for an overview:
Larry Lambert, a former SEAL who has extensive experience with many of the 'players' in the region, has posted two blog articles providing interesting background information:
The crisis there has a direct bearing on the USA's 'War on Terror' - we have a large military base in Qatar, of which Wikipedia reports:
The Al Udeid Air Base now serves as a logistics, command, and basing hub for U.S. operations in Afghanistan and Iraq. Nearby Camp As Sayliyah houses significant U.S. military equipment pre-positioning and command and control facilities for the CENTCOM's area of operations. Both Qatar and the United States have invested in the construction and expansion of these facilities since the mid-1990s, and they form the main hub of the CENTCOM air and ground logistical network in the area of responsibility. As a result of ongoing operations in Iraq and Afghanistan, U.S. and partner nation facilities in Qatar and elsewhere have received higher use in recent years and may require further investment to meet current and potential future needs.
There's more at the link.
Basically, Qatar has been supporting radical Islamic movements and allying itself with Iran, despite being an Arab and Sunni state. The other Arab states in the Persian Gulf are now shutting down access to it, barring food and other imports from and through their territory to Qatar, and blocking its aircraft from using their airspace. In so many words, they're giving Qatar an ultimatum: abandon its support for Iran and radical Islamist movements, or be ostracized by its peer nations.
If Qatar submits, all well and good - but Iran can be expected to move swiftly to make up for the problems caused by the Arab states. If it succeeds, and if the Emir of Qatar stands firm, there may come into being a more radical than ever Islamic axis of terror in the Persian Gulf. That would threaten the USA's primary military base in the region, and therefore also affect its operations in Afghanistan and Iraq. The ripple effects could be very far-reaching indeed.